const num = 3;
export const foo = num;
export const bar = foo!;

const foo1 = 3;
const bar = foo1!;

const foo2 = <3>3;

type Foo3 = 3;
const foo3 = <Foo3>3;

type Foo4 = 3;
const foo4 = 3 as Foo4;

function foo5(x5: number): number {
  return x5!; // unnecessary non-null
}